Railway traffic controlling apparatus



June 23, 1931. w BAUGHMAN 1,810,939 I RAILWAY TRAFFIC CONTROLLING APPARATUS Filed June 18. 1930 INVENTOR G. W Bauqhrnan,

QR-W\ M ATTORNEY Patented June 23, 1931 UNITED STATES PATENT OFFICE GEORGE W. BAUGHMAN, OFPITTSBUBGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SVZISSVALE, PENNSYLVANIA, A CORPORATION. OF

PENNSYLVANIA RAILWAY TRAFFIC CONTROLLING- APPARATUS Application filed, June 18,

My inventionrelates to railway traffic controlling apparatus, and particularly to automatic train control systems of the code type.

One feature of my invention is the pro- Vision in systems of this type, of novel and improved trackway means for insuring the pick-up of a track relay on coded current after the removal of a shunt across the track rails. V

' Iwill describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagra1nmatic view showing one form of trackway apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track rails,- of a railway track along which traiiic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 2 to form a series of track sections, of which only one complete section AB is shown in the drawing.

Located at theentrance end of the section AB is a source of alternating track circuit 15 of which transformer-is constantly connected with terminals X and Y of a source of alternating current. Located at the exit end of the section A -B is a track relay R comprising two windings 3 and 4 and a rotor member 5 which operates two contacts 6 and 1. Relay winding 8 is constantly connected across the track rails through the secondary 9 of a train-controlling transformer T. The primary 8 of the transformer T and the second winding 4 of the track relay R are connected in series across the terminals X and Y of the same source of current as that which supplies the track transformer E.

When the track relay R is energized, so that the front points of its contacts 6 and 7 are closed, the junction point 18 of the transformer primary 8 and the track relay winding 4 is connected through the front polnt of contact 6 with terminal X of the source of current, so that transformer primary 8 is then 1930. Serial No. 461,967.

placed on short circuit, with the result that said primary is deenergized. Current is then supplied to relay winding 4, with the result that this winding is energized.

The reference character C designates a coding device comprising an electric motor 10, a cam 11 driven by motor 10, and a follower 12 cooperating with the cam 11 and operating acontact 13. \Vhen relay R is energized, the coding device is deenergized, so that it is at rest. I Then relay R becomes deencr 'ized, however, so that the back point of contact 6 closes, motor 10 is connected with the terminals X and Y, of the source of alternatingcurrent sothat this motor is then energized to operate the cam 11 and so to oscillate the contact'13. The supply of train governing current to the rails of section -A B is controlled in part by the contact 13'of the coding device C, and in part by a contact 14 of a relay D which is governed by traiiio conditions in advance of section A.B.

As shown in the drawing, section AB is unoccupied so that relay R- is energized, with the result that coding device G is at rest and the train control transformer T is deenergized. If now a train moving in the direction indicated by the arrow enters section A.B, itwill shunt the track circuit current from track relay winding 3, with the result that this relay will become deenergized. When the back point of contact 6 closes, coding device C will-be set into operation to cause contact 13 to oscillate. Assuming that relay 1) is energized, as shown in the drawing,

then when contact l313 is closed, the junction point 18 will be connected with terminal Y of the source of current through the front point of contact 14 of relay D, contact 1313 of the coding device C, and the, back point of contact 7 of relay'R. At this time the primary 8 of transformer T will be connected with terminals X and'Y of the source of current, whereas both terminals oftrack relay winding 4 will be connected with terminal'Y of thesource of current so that this winding will be placed on short circuit. When contact 1318 closes, however, the junction point 18 will be connected with terminal ofthe source of current so that loo 7 transformer primary 8 will be placed on short circuit and relay winding 4 will be supplied with current. In other words, the windings 8 and 4 will be alternately energized, so that alternating current will be periodically supplied to the rails of section A-B for the control of the train-carried apparatus. When theiront end of the train leaves section A 13, it will openrelay D, and whenthe rear end of the train leaves this section, point 18 will be connected with terminal K through the'b ack point of contact 14; of relay D. Relay R will then become energized because of the continuous supply of alternating current to its winding 4, whereupon the apparatus will be restored to its normal condition.

When a shunt is removed from the rails of section A 'B while relay D is energized, it becomes necessary'for relay R topick up on the coded current. Hereto'tore when a code system of train control has been applied to areversedtrack circuit, the circuits 'for relay winding L-and primary winding 8 have been separate and independent, and in such cases it has been found necessary to apply more than normal energy to the track relay in order'to cause the relay to become energized during the For? period of the code, this being due to a strong kick in the re verse direction received the relay during the on period of the code. Vith apparatus embodying my invention this kick is very materially reduced, and I have found that relay, R will become effectively energized without delay by the coded current immediately after a shunt across the rails'has been removed.

Although I have herein shown and de scribed-only one form of apparatusembodying my invention, it is understoodthat variouschanges and modifications may be made therein within "the scope of the appended claims without departing tronrthe'spirit and scopeof myinvention.

I-Iavingthus described my invention, what I claim is:

1. In combination, a section of railway track, a source of alternatingtrack circuit current connected across the mile at one end of'said section, atrack relayhaving two windings'one of whichis connected'across'the rails at theother'end of said section, a train control transformer the secondary. of which is interposed ibetween'the saido'ne winding of said relay and one of the-trackrails, a-ci'rcuit extendingfrom the firstterminalof a source of alternating current through "the primary of saidtransforinerand thesecond winding of said relay to the second terminal. of said source, means operatingwhensaid tr'aclr relay is closed to connect the junction of said-pri- 7 mary and said second relay winding with'the first terminal of said source whereby the primary is then on short c1rcuit,andmeans operating when said track relay is open to alternately connect said j unctionwith the two terminals of said source whereby the primary and the second relay winding are alternately energized and each is on short circuit while the other is energized.

2. In combination, a section of railway track, a source of alternating track circuit current connected across the rails at one end of said section, a track relay having two windings, one of which is connected across the rails at the'other-end ofsaid section, a train control transformer the secondary of which is interposed between one of the track rails and said one relay winding, a circuit including the primary of said transformer and the second relay winding connected in series across a source of alternating current,means operating when said relay is closed to place said primary on short circuit, and means operating when said relay is open to alternately'place said primary and said second relay winding on short circuit. o

3. In combination, a section of railway track, a source of alternating track circuit current connected across the rails at one end of said section, a. track relay having two windings one of which is connected across the rails at the other endofsaid section, atrain control transformer the secondary of which is interposed between one ofthetrack rails and said one relay winding, a circuit including the primary of said transformer and the second relay winding connected in series across a source of alternating current, means operating when said relay is closed to place saidp'rima'ry on short circuit, a coding device comprising a motor and acontact periodically operated thereby, means for energizing saidcoding-device when saidtrack relay is open, and means including said contact and operating when said relay is open to alternately place saidprimary and said second relay winding on'shortcircuit.

r In testimony whereof I affix my signature.

GEORGE WV. BAUGHMAN. 

